The present invention relates to integrated circuits and, more particularly, to an integrated circuit die, two of whose bonding pads, on opposite sides of the die, share a common logical function.
A Multi-Chip Package (MCP) is two or more integrated circuits (ICs), fabricated on respective semiconductor dies such as silicon dies, and packaged in a common package so as to function together as a single “chip”. A System In a Package (SIP) is a MCP in which one of the IC dies is a processor die and the other IC die(s) is/are memory dies, for example flash memory dies or Random Access Memory (RAM) dies. Non-SIP MCPs commonly include memory dies of the same or different types. Among the types of memory dies that commonly are packaged together in MCPs are SDRAM dies, SRAM dies, Pseudo RAM (PSRAM) dies, and flash memory dies such as NAND flash dies and NOR flash dies. MCPs and SIPs are commonly used in consumer appliances such as cellular telephone handsets in order to make the appliances compact.
FIG. 1 is a schematic plan view of the internal structure of a MCP 10 with two stacked IC dies 12 and 14. Die 12 is stacked above die 14, which is on a substrate 16. Both dies 12 and 14 include wire bonding pads 18. Bonding pads 18 of die 12 are connected by electrically conducting wire bonds 20 to bonding pads 18 of die 14. Bonding pads 18 of die 14 are connected by electrically conducting wire bonds 22 to pads (not shown) of substrate 16 that are electrically connected to the pins or balls (not shown) of MCP 10. Alternatively, some or all of the bonding pads 18 of dies 12 and 14, that are connected to each other, are connected to each other via pads of substrate 16, with those bonding pads 18 of dies 12 and 14 connected to those pads of substrate 16 by electrically conducting wire bonds. Alternatively, some of the bonding pads 18 of die 12 are electrically connected directly to the pins or balls of MCP 10. All such electrical connections of bonding pads of one die to bonding pads of another die, that are via only electrical conductors such as wire bonds 20 and/or pads of substrate 16, with no electronic components or electronic circuitry intervening, are considered herein to be “direct” electrical connections.
Vendors of MCPs and SIPs commonly purchase their IC dies from a variety of suppliers. Each supplier typically has its own convention for the layout of bonding pads 18, so that a particular bonding pad 18 of die 12 might have to be bonded to a bonding pad 18 of a die 14 from one supplier that is in a different location from the logically equivalent bonding pad 18 of an equivalent die 14 from a different supplier. The need to adapt a die 12 to two dies 14 with different layouts of their bonding pads 18 (or a die 14 to two dies 12 with different layouts of their bonding pads 14) complicates the internal structure of MCP 10 and the process of assembling MCP 10, or alternatively requires the manufacturing of different versions of the same die, with different pad locations.
There is thus a widely recognized need for, and it would be highly advantageous to have, an IC die that is adapted to assembly in a MCP with a variety of other IC dies with different respective layouts of their bonding pads.